Roman, I agree with most everything you said except for McVay still not being a young coach. Physically he is still a young coach, and exp. wise he's not young but still developing, i.e. not fully mature.
Belichick's first 5 or 6 years were far less impressive. Like you I have criticisms of McVay, but I do see him improving, slowly. I hope the Rams keep him for a long time.